Oil fuse cut-out



June 6, 1939. A. E. PAPP 2,161,427

OIL FUSE CUT-OUT Filed May 15, 1935 3 Sheets-Sheet 1 [warlik- June 6, 1939. A. E. PAPP OIL FUSE CUT-OUT Filed May 15, 1935 3 Sheets-Sheet 2 dad/6w EPapp,

June 6, A p pp OIL FUSE CUT-OUT Filed May 15, 1935 3 Shee'ts-Sheet 3 dad/19 E P Patented June 6, 1939 UNITED STATES PATENT OFFICE OIL FUSE CUT-OUT tion of Illinois Application May 15,

37 Claims.

My invention relates to electric fuse devices and particularly to a type of fuse using oil in connection with the fuse and commonly known as an oil fuse or cutout.

One of the objects of the invention is to provide a simple, practical and advantageous type of electric fuse and particularly an oil fuse or cutout.

Another object of the invention is to secure simplicity of construction with consequent low cost of manufacture and maintenance.

Another object of the invention is to secure a high degree of efhciency of operation.

Another object of the invention is to permit the ready assemblage and disassemblage of the device.

Another object of the invention is to arrange for the quick and easy replacement of a fuse when one has blown.

Another object of the invention is to prevent accidents by short circuits in manipulating the device.

Other objects of the invention will appear and be pointed out hereinafter.

In the accompanying drawings:

Figure 1 is a longitudinal section of an oil fuse or cutout embodying my invention, said section being taken on the line I-I in Figure 2;

Figures 2, 3 and 4 are cross-sections taken on the lines 2-2, 3-8 and 4-4 respectively in Figure 1;

Figures 5 and 6 are cross-sections taken on the lines 5-5 and 6-8 in Figure 4; and

Figure 7 is a detailed view of construction.

In the accompanying drawings I show a cutout involving a casing I which is preferably made of metal and forms the main body of the device. This casing I is preferably to receive oil or other liquid insulating material for purposes in connection with fuses of this kind.

The lower portion of this casing I is preferably provided with apertures in which are fitted insulators 2-2 for the reception of conductors forming part of the circuit which is to include the fuse.

As a preferred arrangement, these insulators 2 are provided with shoulders 3 and separated from the casing I by packing washers 4 which make oil and air tight joints between the insulators and said casing I. Other packing washers 5 are imposed between rings 6 which are secured by bolts 1 to the casing I so as to hold the insulators 2 firmly and tightly in proper position.

Each insulator 2 is preferably provided with a 1985, Serial No. 21,554

terminal 8 having a socket 9 for a conductor, and this terminal 8 is provided with an extension III which may be extended up through an aperture in the upper end of the insulator and secured to a post II, the extension I0 and post II being preferably screw-threaded so that the post II may be firmly screwed into position on top of the insulator 2 and in firm electrical contact -with the extension I0 and terminal 8. A washer I2 of packing or' like material is preferably imposed between the enlarged lower end I3 of post II and top of insulator 2 so as to make a tight joint at the upper end of the insulator. The insulated conductor (not shown) may be led into the lower end of the insulator 2 and secured to the terminal 8 so as to make good electrical connection with terminal 8 and post II and thus by the two insulators 2-2 and their terminals and cooperating parts, provision is made for the connection of two conductors which are to include the fuse of this device in their circuit.

The upper end of casing I is preferably made open, having one flange II with an opening I5 and another flange I6 with an opening I], and into this open end of the casing I a fuse carrying cartridge I8 may be fitted, arrangement being made whereby this cartridge may be inserted into the open end of the casing I to place the fuse in position in the latter, and also whereby the cartridge may be withdrawn either to withdraw the fuse or to provide the cartridge and therefore the circuit with a new one after the fuse has been blown.

This cartridge is preferably composed of a handle portion I9 provided with opening I94: and a body portion 20 which is adapted to fit in the opening II formed by the flange I6. The body portion 20 has the laterally extending and oppositely disposed flanges 20a adapted to be received in the openings 20b formed in the flange ll of the casing I. Upon rotation of the cartridge I8 (as will be later more fully described), flanges 20a are moved beneath flange I4. This body portion 20 has an extension 2| adapted to extend inwardly, and this extension carries a hollow or chamber member 22 having a chamber 23 and side openings 24 whereby the interior of chamber 23 may be in communication with the interior of easing I and therefore may contain 01] when the latter is provided with oil.

A fuse 25 is shown carried by the member 22 and extended across the chamber 23 and having its ends passing through apertures 24, so that the fuse is not only carried by the cartridge member 20 but is also immersed in oil when the device is in operative condition. The member 22 is preferably of some insulating material, as for example Ebonite, so as to afford good insulation for the fuse 25 and its associated parts.

The fuse 25 is preferably subjected to spring pressure tending to elongate so that when it blows the spring pressure or action will tend to separate the fuse or its parts and thereby lengthen the fuse gap and elongate the arc. As a simple and advantageous arrangement, spring members 21 (Figure 7) are preferably mounted on the chamber member 22 and interposed between the fuse and said member 22 so that they tend to spring outwardly and thereby exert a pressure on the fuse tending to elongate it. These springs 21 may be held in position by screws 29, passing through apertures in the spring and these screws also hold the ends of the fuse in place, passing through apertures 3| of the same. This mounting is shown best in Figures 1, 3, 4, 5 and 6, particularly in Figure 3. The screws 29 are preferably provided with wing nuts 32 and are mounted on side portions or extensions 33 and 33a of the chamber member 22.

Each screw 29 is provided with a hex or like nut 34 and an enlarged threaded inner end 35 which screws into a plate 36 on each of the extensions 33 and 33a, and a clip 31 is interposed betweenv wing-nut 32 and fuse 25 and later arranged between clip 31 and hex nut 34, and spring 21 in .turn between nut 34 and plate 36. Clip 31 has a curved end 38 adapted to contact and press against fuse 25 (Figure 3), and an inturned end 39 which works alongside plate 36.

By this arrangement spring 21 may be put in position, as shown in Figure 3, and then end 35 of screw 23 screwed into plate 36 to hold spring 21 firmly in position. Then end of fuse 25 may be put in position on the outer side of nut 34 and then clip 31 put in place and nut 32 screwed down to force clip 31 tightly against fuse 25 and so draw down on same to tighten fuse 25 against spring 21 and so produce an adequate tension on the fuse.

When the fuse blows, the ends of springs 21 spring outwardly and separate the arc ends and so lengthen the fuse gap and tend to extinguish the arc. Oil is in the outer chamber and also in inner fuse chamber 23, and this is forced outwardly in the chambers and through the apertures 24 and thereby further assists in extinguishing the arc. After operation, a new fuse 25 is inserted, as described above.

To connect fuse in circuit and also permit insertion and removal of cartridge containing fuse, I show as one arrangement the structure illustrated in Figures 1, 4, 5 and 6. In this arrangement two sets of contact clips are provided, each set comprising clips 40 and H, having flat shanks 42 and 43 respectively, adapted to be secured to plate 36 by screw 44. Said clips 40 and 4| also have contact portions 45 and 46 respectively, sufficiently separated to permit contact posts II to pass between them, but to make firm electrical contact and connection with same. Clips 41 are provided in connection with contacts 4|, said clips 41 having outwardly extending portions 46 backing clips 4| and holding same in better contact with posts II.

The connection between posts II, II and contact clips or devices 40, 4|, is made by turning or partially rotating fuse carrying cartridge I8 so as to cause clips 40, 4| to embrace posts I I, II, as shown in Figure 5, or else to separate from said posts by an anti-clockwise movement (indicated by dotted arrows) in Figure 5.

In order to guard against inserting the cartridge I8 into the casing I in such a position that contacts 40 and 4| would not engage terminal members I within the limits of rotation as above indicated, openings 2Ia and 2Ib are provided in flange I4 of easing I for receiving the edge portions of extensions 33a and 33, respectively. The edge portion of extension 330. is of less width than the edge portion of extension 33 and slot or opening 2 la is of less width than slot or opening 2Ib, slot 2Ia being too narrow to receive extension 33. It.will therefore be apparent that cartridge |8 can be inserted into place in casing I in one position only. When inserted in the correct manner contacts 40 and 4| are in position to engage terminals upon rotation of the cartridge I8.

This rotative movement of fuse cartridge to connect and disconnect the fuse in circuit, may be made by turning said cartridge handle I9, either by hand or by inserting a stick, or the like, within opening Isa, and the arrangement is preferably such that the cartridge may be inserted and withdrawn when the fuse is out of circuit, but is locked against insertion and withdrawal when the fuse is in circuit. This prevents the cartridge from being accidentally blown out or other damage done by inadvertently connecting the fuse in circuit when there is a short or other trouble on the line.

This is accomplished by providing a swinging yoke or bail 50 pivoted by pins 5| to sides of casing I (Figure 1) so that it may swing into and out of path of cartridge I8 to permit control of the latters insertion and withdrawal and locking in place. The yoke or ball 50 is preferably provided with an adjustable screw 54 with lock nut 55, and the cartridge handle III with channel 56 for receiving the end of screw 54. When the cartridge handle I9 is in such position that channel 56 is crosswise of ball 50 to permit screw 54 to move in said channel (Figure 2), contacts 40 and 4| are not connected to posts II, II and cartridge may safely be inserted and withdrawn, and the ball 50 may be swung to bring screw 54 into and out of said channel. If screw 54 is moved out of said channel, bail 50 is swung to one side and cartridge may be removed. If, however, when screw 54 is in channel 56, cartridge is turned to bring contacts 40, 4| in contact with posts II, the fuse is connected in circuit, but at the same time channel is inclined so that screw 54 cannot move out of channel 56 (see Figure 1) and so fuse cartridge is locked against being withdrawn or blown out.

Means is further provided to prevent rotation of cartridge I8 which would bring contacts 40 and H into engagement with posts or terminals II after the cartridge has been rotated to effect a disengagement thereof and the ball 50 has been lowered into its horizontal position. Such means comprises a lug 60 disposed on the bail 50 and a stop pin 62 fixed to the casing I. Lug 60 is normally disposed below the top 64 of cartridge l8 when the bail is vertically disposed whereby the bolt 54 engages in channel 56 but is adapted, upon rotation of bail 50, to move through opening 66 in top 64 into opposite relation to shoulder 68 defining one end of opening 66. As shown in Figure 2 of the drawings, the top 64 is provided with an arrow 10 indicated in full to show the position thereof when the cartridge is in its off position, that is, when contacts 40 and ll are out of engagement with the terminals or posts If and indicated in dotted lines to show the position thereof when the cartridge is in its on position", namely, when the contacts 40 and II are in engagement with terminals II, Rotation of cartridge it between its ofl."' and "on positions is limited by stop pin .62 engageable with lug I! when in oil position and with lug I4 when in on" position.

Precaution has been taken, therefore, to provide a fuse cutout in which the fuse cartridge can be inserted in place in one position only, and can be inserted and withdrawn only when the fuse is out of circuit, provision also being made to prevent placing said fuse in circuit prior to the locking of the same after insertion or when said locking means is ineffective when the cartridge is disposed for withdrawal.

A pipe 58 leading into the top of casing I is provided which serves as a cushion or expansion chamber whenever a heavy circuit is interrupted within the oil fuse cutout and to prevent an undue severe strain from-being put on the housing or casing I.

It will be understood that changes and modiflcations may be made without departing from the spirit of the invention.

I claim:

1. An oil switch comprising an outer casing, an-inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse under spring tension, and contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, one of said contact devices being carried by said inner casing and being disposed in spaced relation to said outer casing and the other of said contact devices extending through the end wall opposite the open end of said outer casing and into the same, said contact devices comprising contact posts and open-jawed spring clips to clasp and make contact with said posts.

2. An oil switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse under spring tension, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, one of said contact devices being carried by said inner casing and being disposed in spaced relation to said outer casing and the other of said contact devices extending through the end wall opposite the open end of said outer casing and into the same, said contact devices comprising contact posts and open-jawed spring clips to clasp and make contact with said posts, and cooperating clips to back spring clips and help maintain close connection:

3. An oil switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse under spring tension, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, said contact devices comprising contact posts extending through the end wall opposite the open end of said outer casing and into the same and open-jawed spring clips connected to said inner casing to clasp and make contact with said posts, cooperating clips to back spring clips, and means whereby the inner casing may be locked against insertion and removal when the fuse is connected in circuit.

4. An oil switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse under spring tension, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, said contact devices comprising contact posts and open-jawed spring clips to clasp and make contact with said posts, cooperating clips to back spring clips, and means whereby the inner casing may be locked against insertion and removal when the fuse is connected in circuit, said means comprising a locking bail, and cooperating means on said bail and inner casing operable only when said fuse is out of said circuit permitting movement of said bail.

5. An oil switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse under spring tension, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, said contact devices comprising contact posts and open-jawed spring clips to clasp and make contact with said posts, cooperating clips to back said spring clips, and means whereby the inner casing may be locked against insertion and removal when the fuse is connected in circuit, said means comprising a locking bail and means whereby said bail may prevent and permit the insertion and withdrawal of inner casing, said ball being provided with an adjustable screw and the inner casing with a channel to receive said screw and permit or prevent movement of screw in channel according to position of inner casing.

6. An oil fuse comprising an outer casing and a fuse cartridge insertable into said casing, said cartridge having a fuse chamber and oppositely disposed laterally extending portions, a fuse extending through said chamber and having its ends connected to opposite faces of said portions, and springs on said oppositely disposed faces adapted to engage and press transversely on said fuse to maintain said fuse within said chamber under tension.

7. An oil fuse comprising an outer casing and a fuse cartridge insertable into said casing, said cartridge having a fuse chamber and oppositely disposed laterally extending portions, posts arranged on opposite faces of said portions, a fuse extending through said chamber and having its ends connected to said oppositely disposed posts, springs connected to said posts between said portions and fuse adapted to engage and press transversely on said fuse to maintain said fuse under tension, and spring clips connected to said posts exteriorly of said fuse to form a backing for the same.

8. An oil fuse comprising an outer casing and a fuse cartridge insertable into said casing and provided with fuse and spring clips arranged to press transversely of fuse at ends of same and thereby maintain fuse under tension, said fuse being extended to posts and spring clips being interposed between fuse and posts and pressing outwardly on fuse, said posts having abutments for fuse and spring clips and other clips on post to assist in tightening fuse against spring clips.

9. An oil fuse comprising an outer casing and a fuse cartridge insertable into said casing and provided with fuse and spring clips arranged to press transversely of fuse at ends of same and thereby maintain fuse under tension, said fuse being extended to posts and spring clips being interposed between fuse and posts and pressing outwardly on fuse, said posts having abutments for fuse and spring clips and other clips on post to assist in tightening fuse against spring clips, and contact devices for including fuse in circuit, said devices being mounted on and secured to metal plate which also carries said spring and fuse arrangement.

10. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse; contact devices on the inner and outer casings for making connection to include the fuse in circuit, and means for locking said inner casing to said outer casing, and control means associated with said first-named means whereby said first-named means is operable from looking to unlocking position to permit withdrawal of said inner casing only when said fuse is out of circuit.

11. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, means for locking said inner casing to said outer casing, and means preventing said rotation when said locking means is in its unlocked position.

12. A switch comprising an outer casing, an-

inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, and means for locking said inner casing to said outer casing, said means being operable to unlock only after rotation to move said fuse out of circuit.

13. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, means for locking said inner casing to said outer casing, and means to prevent said rotation to place said fuse in circuit until after said locking means has been operated to lock said inner casing to said outer casing, said locking means being operable to unlock only after rotation to move said fuse out of circuit.

14. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, pivotal locking means on said outer casing cooperating with said inner casing to lock said casings together, and cooperating means on said locking meansand inner and outer casings preventing rotation of said inner casing when said locking means is in its unlocked position.

15. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, pivotal locking means on said outer casing cooperating with said inner casing when said inner casing has been rotated to place said fuse in circuit to lock said casings, and cooperating means on said locking means and inner casing preventing said rotation to place said fuse in circuit when said locking means is in its unlocked position.

16. A switch comprising an outer casing memher, an inner fuse carrying member adapted to be inserted into and withdrawn from the outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, means for locking said inner member to said outer member, cooperating means on said inner and outer members for preventing introduction of said fuse into said circuit when said locking means is inoperative to lock said inner member in said outer member, and means for preventing operation of said locking means from looking to unlocking position while said fuse is in circuit.

17. A switch comprising an outer casing member, an inner fuse carrying member adapted to be inserted into and withdrawn from the outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, and cooperating means on said inner and outer members for looking said inner member to said outer member, said locking means being so constructed and arranged that movement of said locking means from looking to unlocking position is prevented until said fuse is withdrawn from said circuit.

18. A switch comprising an outer casing member, an inner fuse carrying member adapted to be inserted into and withdrawn from the outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, means for locking said inner member to said outer member, and means for preventing introduction of said fuse into said circuit when said locking means is inoperative to lock said inner member in said outer member, and means for preventing operation of said locking means from looking to unlocking position while said fuse is in circuit.

19. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, pivotal locking means on said outer casing cooperating with said inner casing to lock said casings together, and said locking means and inner casing having means normally cooperating to lock said inner casing to said outer casing, said means being so constructed and arranged as to be operable to permit operation of said pivotal locking means from looking to unlocking position only when said fuse is out of circuit.

20. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, pivotal locking means on said outer casing cooperating with said inner casing when said inner casing has been rotated to place said fuse in circuit to lock said casings, and said locking means and inner casing having cooperating means preventing rotation of said inner casing to place said fuse in circuit when said locking means is in its unlocked position, and means normally cooperating to lock said inner casing to said outer casing, said means being so constructed and arranged as to be operable to permit operation of said pivotal locking means from looking to unlocking position only when said fuse is out of circuit.

21. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, a locking bail pivoted to said outer casing and having an inwardly disposed member engageable with said inner casing for locking the same in said outer casing, and cooperating lugs on said ball and inner and outer casings preventing rotation of said inner casing when said bail is in its unlocked position.

22. A switch comprising an outer casing, an inner casing adapted to be inserted into and withdrawn from the outer casing and carrying a fuse, contact devices on the inner and outer casings for making connection to include the fuse in circuit when the inner casing is inserted and given a partial rotation, a locking bail pivoted to said outer casing and having an adjustable inwardly disposed member engageable with said inner casing for locking the same in said outer casing, and cooperating lugs on said ball and inner and outer casings preventing rotation of said inner casing when said ball is in its unlocked position.

23. A switch comprising an outer casing memher, an inner fuse carrying member adapted to be inserted into and withdrawn from said outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, said inner member having a channel, and swingable locking means for said inner member provided with a portion adapted to be received in said channel, said channel having means disposed to receive said portion only when said fuse is out of circuit.

24. A switch comprising an outer casing member, an inner fuse carrying member adapted to be inserted into and withdrawn from said outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, said inner member having a channel, and swingable locking means for said inner member provided with a portion adapted to be received in said channel, said channel havingmeans disposed to receive said portion only when said fuse is out of circuit and to prevent removal of said portion therefrom to unlock said locking means when said fuse is in circuit.

25. A switch comprising an outer casing member, an inner fuse carrying member adapted to be inserted into and withdrawn from said outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, said inner member having a channel, and swingable locking means for said inner member provided with a portion adapted to be received in said channel,

said channel having means disposed to receive said portion only when said fuse is out of circuit, and means preventing movement of said fuse into circuit until after said portion isreceived in said channnel.

26. A switch comprising an outer casing member, an inner fuse carrying member adapted to be inserted into and withdrawn from said outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, said inner member having a channel, and swingable locking means for said inner member provided with a portion adapted to be received in said channel, said channel having means disposed to receive said portion only when said fuse is out of circuit and to prevent removal of said portion therefrom to unlock said locking means when said fuse is in circuit, and means preventing movement of said fuse into circuit until after said portion is received in said channel.

27. A switch comprising an outer casing member, an inner fuse carrying member adapted to be inserted into and withdrawn from said outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, said inner memher having a channel, and swingable locking means for said inner member provided with a portion adapted to be received in said channel, said channel having means disposed to receive said portion only when said fuse is out of circuit, and means on said outer member and locking means cooperating with said inner member preventing movement of said fuse into circuit until after said portion is received in said channel.

28. A switch comprising an outer casing member, an inner fuse carrying member adapted to be inserted into and withdrawn from said outer member, contact devices on the inner and outer members for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, said inner member having a channel, and swingable locking means for said inner member provided with a portion adapted to be received in said channel, said channel having means disposed to receive said portion only when said fuse is out of circuit and to prevent removal of said portion therefrom to unlock said locking means when said fuse is in circuit, and means on said outer member and locking means cooperating with said inner member preventing movement of said fuse into circuit until after said portion is received in said channel.

29. In a switch, the combination of a rotatable support, contact devices on opposite faces of said support and disposed in opposed relation, each of said devices comprising spring clips connected to said support at one end and being spaced apart at the other end, and a backing clip connected at one end to said support and having the remaining portion thereof in backing relation to one of said clips.

30. In a switch, the combination of a support provided with terminals, a fuse extending therebetween, springs adjacent the end portions of said fuse, and oppositely disposed clip members, said springs and clip members acting to hold said fuse taut.

31. In a switch, the combination of a support provided with terminals, a fuse extending therebetween, springs adjacent the end portions of said fuse and engaging the faces of said fuse, and oppositely disposed clip members engaging the opposite faces of said fuse in spaced relation to said springs whereby said fuse is maintained in taut relation therebetween.

32. An oil fuse comprising an outer casing and a fuse cartridge insertable into said casing, said cartridge having a transverse fuse chamber and oppositely disposed openings in the wall of said chamber and leading into the same, a fuse extending through said openings and being connected adjacent its ends to said cartridge exteriorly of said chamber, and springs connected to said cartridge adjacent the ends of said fuse and cooperating therewith to maintain said fuse within said chamber under tension.

33. A switch comprising an outer casing, an inner fuse carrying member adapted to be inserted into and withdrawn from said outer casing, contact devices on the inner member and on said outer casing for making connection to include the fuse in circuit when the inner member is disposed within said outer casing, and a swingable locking member for said inner member, one of said members having a channel and the other of said members having means adapted to be received in said channel, said channel having means disposed to receive said last-named means only when said fuse is out of circuit.

34. In a switch, the combination of a fuse cartridge having a fuse chamber provided with oppositely disposed openings in the wall of said chamber and leading into the same, contact devices secured to said cartridge in opposed relation exteriorly of said chamber, a fuse extending through said openings and being connected adjacent its ends to said contact devices, and springs connected to said cartridge and cooperating with said fuse to maintain the same within said chamber under tension.

35. In a switch, the combination of a fuse cartridge having a fuse chamber provided with oppositely disposed openings in the wall of said chamber and leading into the same, contact devices secured to said cartridge in opposed relation exteriorly of said chamber, said devices including an electrical conducting member secured to opposite faces of said cartridge, a fuse extending through said openings and being connected adacent its ends to said members, and springs connected to said members and cooperating with said fuse to maintain the same within said chamber under tension.

36. In a switch, the combination of a fuse cartridge having a fuse chamber provided with 01)- positely disposed openings in the wall of said chamber and leading into the same, electrical conducting members secured to opposite faces of said cartridge, spring clips connected to said members in opposed relation, a fuse extending through said openings and being connected adjacent its ends to said members, and a spring connected to each of said members and cooperating with said fuse to maintain the same within said chamber under tension.

3'7. In a switch, the combination of a fuse cartridge having a fuse chamber provided with oppositely disposed openings in the wall ofsaid chamber and leading into the same, electrical conducting members secured to opposite faces of said cartridge, open-jawed spring clips connected to said members in opposed relation, a backing clip connected to each of said members and having a portion thereof in backing relation to the outer of said spring clips, a fuse extending through said openings and being connected adjacent its ends to said members, a spring connected to each of said members and cooperating with said fuse to maintain the same within said chamber under tension, and a spring clip connected to each of said members forming a backing for said fuse.

ANDREW E. PAPP. 

